omni-node: add metadata checks for runtime/parachain compatibility

[iulianbarbu]

Description

Get runtime's metadata, parse it and verify pallets list for a pallet named ParachainSystem (for now), and block number to be the same for both node and runtime. Ideally we'll add other pallets checks too, at least a small set of pallets we think right away as mandatory for parachain compatibility.
Closes: #5565

Integration

Runtime devs must be made aware that to be fully compatible with Omni Node, certain naming conventions should be respected when defining pallets (e.g we verify parachain-system pallet existence by searching for a pallet with name ParachainSystem in runtime's metadata). Not finding such a pallet will not influence the functionality yet, but by doing these checks we could provide useful feedback for runtimes that are clearly not implementing what's required for full parachain compatibility with Omni Node.

Review Notes

• parachain system check
• check frame_system's metadata to ensure the block number in there is the same as the one in the node side
• add tests for the previous checking logic
• update omni node polkadot-sdk docs to make these conventions visible.
• add more pallets checks?

[paritytech-cmd-bot-polkadot-sdk]

Created backport PR for stable2407:

• [stable2407] Backport #6450 #6871 with remaining conflicts!

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin backport-6450-to-stable2407
git worktree add --checkout .worktree/backport-6450-to-stable2407 backport-6450-to-stable2407
cd .worktree/backport-6450-to-stable2407
git reset --hard HEAD^
git cherry-pick -x 7cc5cdd0d98ae3466dc33b339197c169cf241fc0
git push --force-with-lease

[paritytech-cmd-bot-polkadot-sdk]

Created backport PR for stable2409:

• [stable2409] Backport #6450 #6872 with remaining conflicts!

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin backport-6450-to-stable2409
git worktree add --checkout .worktree/backport-6450-to-stable2409 backport-6450-to-stable2409
cd .worktree/backport-6450-to-stable2409
git reset --hard HEAD^
git cherry-pick -x 7cc5cdd0d98ae3466dc33b339197c169cf241fc0
git push --force-with-lease

[paritytech-cmd-bot-polkadot-sdk]

Created backport PR for stable2412:

• [stable2412] Backport #6450 #6873 with remaining conflicts!

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin backport-6450-to-stable2412
git worktree add --checkout .worktree/backport-6450-to-stable2412 backport-6450-to-stable2412
cd .worktree/backport-6450-to-stable2412
git reset --hard HEAD^
git cherry-pick -x 7cc5cdd0d98ae3466dc33b339197c169cf241fc0
git push --force-with-lease